import static org.junit.Assert.*;
import org.junit.Before;
import org.junit.Test;

public class Main {
    private Expression expr;

    @Before
    public void setUp() throws Exception {
        expr = new Expression(5, 3, '+');
    }

    @Test
    public void testCalculate() {
        assertEquals(8, expr.calculate());
    }

    @Test
    public void testToString() {
        assertEquals("5 + 3", expr.toString());
    }
}